The single-tablet regimen of the hepatitis C virus (HCV) NS5A inhibitor ledipasvir and the HCV NS5B polymerase inhibitor sofosbuvir (ledipasvir/sofosbuvir; Harvoni®) was recently approved in the US and the EU. The phase III ION trials included treatment-naive (ION-1 and -3) or treatment-experienced (ION-2) patients with chronic HCV genotype 1 infection (≈20 % of patients in ION-1 and -2 had cirrhosis, whereas no patient in ION-3 had cirrhosis). A sustained virological response 12 weeks' post-treatment (SVR12) was seen in 99 % of treatment-naive patients receiving ledipasvir/sofosbuvir for 12 weeks in ION-1, with no additional benefit conferred by the addition of ribavirin or extending the treatment duration to 24 weeks. Moreover, in ION-3, an 8-week regimen achieved an SVR12 rate of 94 % overall and 97 % in the subgroup of patients with a baseline HCV RNA level of <6 million IU/mL. SVR12 rates of 94 and 99 % were seen in treatment-experienced patients who received ledipasvir/sofosbuvir for 12 and 24 weeks in ION-2. Data also support the use of ledipasvir/sofosbuvir in chronic HCV genotype 4 infection, in HCV and HIV co-infection and, in combination with ribavirin, in patients with chronic HCV genotype 1 or 4 infection who have decompensated cirrhosis or are liver transplant recipients and in chronic HCV genotype 3 infection. Oral ledipasvir/sofosbuvir was generally well tolerated. In conclusion, ledipasvir/sofosbuvir is an important new single-tablet regimen that represents a significant advance in the treatment of chronic hepatitis C.